使用 vanilla JavaScript 自定义数据聚合

Question

您能帮我解决以下数据聚合问题吗？

这是我的初始数组：

const data = [
    { date: '2023-11-01', type: 'A', casualties: 10, state: 'NY', country: 'USA', site: 'hash1' },
    { date: '2023-11-01', type: 'B', casualties: 5, state: 'NY', country: 'USA', site: 'hash2' },
    { date: '2023-11-02', type: 'A', casualties: 15, state: 'NY', country: 'USA', site: 'hash3' },
    { date: '2023-11-01', type: 'C', casualties: 20, state: 'NY', country: 'USA', site: 'hash4' },
    { date: '2023-11-02', type: 'B', casualties: 8, state: 'NY', country: 'USA', site: 'hash5' },
    { date: '2023-11-03', type: 'A', casualties: 25, state: 'NY', country: 'USA', site: 'hash6' },
    { date: '2023-11-01', type: 'D', casualties: 12, state: 'NY', country: 'USA', site: 'hash7' },
];

我想根据

other

值聚合

casualties

类型下的部分行。

如果给定

type

的所有日期的

casualties

等于或高于某个阈值，则它应该是

results

数组的一部分。

如果给定

type

的

casualties

低于所有日期的阈值，但它是唯一低于阈值的

type

，则它将成为

results

数组的一部分。

如果所有日期中有两个或多个

types

的

casualties

低于特定阈值， 它们不应该是

results

数组的一部分。对于这种情况，

casualties

将针对每个日期进行求和，并且

type

值应为

other

。

otherCasualties

数组应包含

types

低于所有日期阈值的所有

casualties

。

示例：

如果

casualtiesThreshold

是

9

，则

results

数组应该是：

results = [
    { date: '2023-11-01', type: 'A', casualties: 10, state: 'NY', country: 'USA' },
    { date: '2023-11-01', type: 'B', casualties: 5, state: 'NY', country: 'USA' },
    { date: '2023-11-02', type: 'A', casualties: 15, state: 'NY', country: 'USA' },
    { date: '2023-11-01', type: 'C', casualties: 20, state: 'NY', country: 'USA' },
    { date: '2023-11-02', type: 'B', casualties: 8, state: 'NY', country: 'USA' },
    { date: '2023-11-03', type: 'A', casualties: 25, state: 'NY', country: 'USA' },
    { date: '2023-11-01', type: 'D', casualties: 12, state: 'NY', country: 'USA' },
];

并且

otherCasualties

数组应该是

[]

。

如果

casualtiesThreshold

是

13

，则

results

数组应该是：

results = [
    { date: '2023-11-01', type: 'A', casualties: 10, state: 'NY', country: 'USA'},
    { date: '2023-11-01', type: 'other', casualties: 17, state: 'NY', country: 'USA' },
    { date: '2023-11-02', type: 'A', casualties: 15, state: 'NY', country: 'USA' },
    { date: '2023-11-01', type: 'C', casualties: 20, state: 'NY', country: 'USA' },
    { date: '2023-11-02', type: 'other', casualties: 8, state: 'NY', country: 'USA' },
    { date: '2023-11-03', type: 'A', casualties: 25, state: 'NY', country: 'USA' },
];

并且

otherCasualties

数组应该是

['B', 'D']

。

这是我尝试过的：

function processCasualties(data, casualtiesThreshold) {
  const results = [];
  const otherCasualties = [];

  const groupedData = data.reduce((acc, item) => {
    const key = item.type;
    if (!acc[key]) {
      acc[key] = [];
    }
    acc[key].push(item);
    return acc;
  }, {});

  const types = Object.keys(groupedData);

  types.forEach(type => {
    const typeData = groupedData[type];
    const totalCasualties = typeData.reduce((acc, item) => acc + item.casualties, 0);
    const allDatesBelowThreshold = typeData.every(item => item.casualties < casualtiesThreshold);

    if (totalCasualties >= casualtiesThreshold || (allDatesBelowThreshold && types.length === 1)) {
      results.push(...typeData.map(item => ({
        date: item.date,
        type: item.type,
        casualties: item.casualties,
        state: item.state,
        country: item.country,
      })));
    } else if (allDatesBelowThreshold) {
      otherCasualties.push(type);
    } else {
      results.push(...typeData.map(item => ({
        date: item.date,
        type: 'other',
        casualties: totalCasualties,
        state: item.state,
        country: item.country,
      })));
    }
  });

  return { results, otherCasualties };
}

const casualtiesThreshold = 13;

const { results, otherCasualties } = processCasualties(data, casualtiesThreshold);

console.log(results);
console.log(otherCasualties);

Answer 1

您可以采取两组并在第一次迭代中收集匹配的类型和其他类型。然后删除

other

集中匹配的类型，因为这些类型应该在结果集中。

最后检查

other

集中是否只有一种类型，然后将该类型也添加到结果中。

对于所有其他不匹配类型，采用

'other'

作为类型，按

date

分组。

const
    fn = (data, threshold) => {
        const
            result = [],
            other = new Set,
            match = new Set,
            others = {};
        
        for (const { type, casualties } of data) [other, match][+(casualties >= threshold)].add(type);
        
        match.forEach(Set.prototype.delete, other);
        
        if (other.size === 1) {
            match.add(...other);
            other.clear();
        }
        
        for (const { date, type, casualties, state, country, site } of data) {
            if (match.has(type)) {
                result.push({ date, type, casualties, state, country, site });
            } else {
                if (others[date]) others[date].casualties += casualties;
                else result.push(others[date] = { date, type: 'other', casualties, state, country, site });
            }
        }

        return { result, otherCasualties: [...other] };
    },
    data = [{ date: '2023-11-01', type: 'A', casualties: 10, state: 'NY', country: 'USA', site: 'hash1' }, { date: '2023-11-01', type: 'B', casualties: 5, state: 'NY', country: 'USA', site: 'hash2' }, { date: '2023-11-02', type: 'A', casualties: 15, state: 'NY', country: 'USA', site: 'hash3' }, { date: '2023-11-01', type: 'C', casualties: 20, state: 'NY', country: 'USA', site: 'hash4' }, { date: '2023-11-02', type: 'B', casualties: 8, state: 'NY', country: 'USA', site: 'hash5' }, { date: '2023-11-03', type: 'A', casualties: 25, state: 'NY', country: 'USA', site: 'hash6' }, { date: '2023-11-01', type: 'D', casualties: 12, state: 'NY', country: 'USA', site: 'hash7' }];
    
console.log(fn(data, 9));
console.log(fn(data, 13));

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